Knocked-out boxers never the same again

De la Hoya said the next time Pacquiao steps inside the ring, he will always be looking out for the same punch that knocked him out.

"Psychologically he is always going to be feeling that punch. He's always going to be looking out for that punch," De la Hoya, who succumbed to Pacquiao in eight rounds, said in Boxing Scene.

Pacquiao suffered his first knockout loss since 1996 when his mistakenly walked into Marquez counter right hand in the sixth round of their fight.

The Filipino boxer already had Marquez on the ropes and was going for the kill before he was caught by the knockout punch.

De la Hoya said the stunning loss will seriously affect Pacquiao’s confidence inside the ring.

“He will be doubting himself [and telling himself] 'can I do this again.' - even in training, even in training [he will be doubting himself],” said De la Hoya.

He added that boxing history proves that most boxers were never the same after being knocked out cold by their opponents.

“You look at Paul Williams [at how he got knocked out]. Back in the day Thomas Hearns knocked out Roberto Duran and he landed face first. You look at Ricky Hatton at how he got knocked out. You look at history in boxing," said De La Hoya.